Morphing Air Conditioner into Autocascade System

[mytekcontrols]

So lets say you add that 2nd phase separator, and another heat exchanger. R123, r22, r23 is still viable?

Yes it should be. In fact Polycold has a system called a PGC-150 that utilizes this many stages, and the same refrigerants (although it does have a subcooler and small amounts of R-14 and Argon as well). It does -120C at just over 300 watts, and utilizes a 1 1/2 HP reciprocating compressor.

But if you are just starting out with autocascade design, it is better to keep it simple, and build up from what you learn.

Edit: the PGC-150 also uses Ethane as part of its blend.